Preliminary Research on Dual-Energy X-Ray Phase-Contrast Imaging

Dual-energy X-ray absorptiometry (DEXA) has been widely applied to measure bone mineral density (BMD) and soft-tissue composition of human body. However, the use of DEXA is greatly limited for low-Z materials such as soft tissues due to their weak absorption. While X-ray phase-contrast imaging (XPCI) shows significantly improved contrast in comparison with the conventional standard absorption-based X-ray imaging for soft tissues. In this paper, we propose a novel X-ray phase-contrast method to measure the area density of low-Z materials, including a single-energy method and a dual-energy method. The single-energy method is for the area density calculation of one low-Z material, while the dual-energy method is aiming to calculate the area densities of two low-Z materials simultaneously. Comparing the experimental and simulation results with the theoretic ones, the new method proves to have the potential to replace DEXA in area density measurement. The new method sets the prerequisites for future precise and low-dose area density calculation method of low-Z materials.Comment: 7 pages, 5 figure

Use of quantitative ultrasound scans of the calcaneus to diagnose osteoporosis in patients with rheumatoid arthritis

Background: Patients with rheumatoid arthritis are recognized as being at risk for osteoporosis as a result of the disease process as well as the medication used to treat it. This study was conducted to consider the use of calcaneal scanning with quantitative ultrasound—contact ultrasound bone analysis (CUBA)—to diagnose osteoporosis in patients with rheumatoid arthritis.Methods: Forty-six patients (11 men and 35 women) with established rheumatoid arthritis underwent dual-energy x-ray absorptiometry (DEXA) of the nondominant wrist andCUBA of the nondominant heel. Sensitivity, specificity, and positive and negative predictive values were used to determine the correlation between osteoporosis as diagnosedby the CUBA heel scan compared with the DEXA wrist scan given that DEXA is widely seen as the gold standard for the diagnosis of osteoporosis.Results: The CUBA heel scan revealed a sensitivity of 90% and a specificity of 44% for a diagnosis of osteoporosis compared with DEXA. The positive predictive value of theCUBA scan was 31%, and the negative predictive value was 94%. Therefore, if normal bone density is found using CUBA, there is 94% certainty this is correct. However, if osteoporosis is diagnosed using CUBA, there is only 31% certainty this is correct. In such instances a secondary scan using a different method (eg, DEXA) would be required. Future work should consider the effect of minor alterations to the equipment or scanning protocol, because this may improve diagnosis.Conclusions: The CUBA unit could be used as a primary screening device. Given the cost and accessibility issues associated with DEXA, quantitative ultrasound may have arole in screening for osteoporosis in the primary-care setting to determine the most appropriate routes of referral for patients requiring further investigations. <br/

Measurement of bone quality in growing male rats using dual energy x-ray absorptiometry and bone ash content : a thesis presented in partial fulfilment of the requirements for the degree of Master of Applied Science in Animal Science at Massey University, Palmerston North, New Zealand

Growing male rats have been considered and used as a model for bone growth and prevention of osteoporosis because of their high bone turnover and demand for calcium. Dual Energy X-ray Absorptiometry (DEXA) is a useful tool for identifying minimal changes in bone mineral density and has recently been adapted for use in small animal models. The objective of this trial was to identify the changes in Bone Mineral Density (BMD) in relation to age and to identify how BMD varies from site to site. Sixty male Sprague-Dawley rats were split into six groups to allow measurements at one, two, three, four, five and six months of age (n=10 per group). At each time point a group of rats was scanned using a QDR4000 DEXA machine from Hologic. Duplicate BMD measurements were obtained for the whole body, spine and both femurs in vivo. The rats were then euthanased and the spine and both femurs were excised for ex vivo DEXA scanning and ashed calcium analysis. BMD increased almost linearly to four months and then formed a plateau. This indicates that from weaning to four months is an especially sensitive time for manipulating bone growth in male rats. There was a significant difference in BMD between groups (P<0.001), which is to be expected in growing rats. There was also a significant difference in BMD within groups (p<0.001), believed to be due to variation at two and five months of age. There was a very strong positive correlation between weight and BMD and age and BMD at all sites, indicating that BMD is a strongly related to both weight and age. All sites were strongly correlated to each other and to the ashed calcium values. The excised femur had a lower BMD value than the in vivo femur, although the two values were strongly correlated. This is believed to be due to differences in positioning and indicates that the two methods cannot be used interchangeably. These results indicate that bone mineral density is the gold standard for following changes in bone growth over time in the growing rat. Alternatively, ashed bone calcium content can be used, but only as a once off endpoint

Bone mineral density and fracture risk with long-term use of inhaled corticosteroids in patients with asthma: systematic review and meta-analysis

Objectives: We aimed to assess the association between long-term use of inhaled corticosteroids (ICS) and bone adverse effects in patients with asthma. Design: Systematic review and meta-analysis of fracture risk and changes in bone mineral density with long-term ICS use in asthma. Methods: We initially searched MEDLINE and EMBASE in July 2013, and performed an updated PubMed search in December 2014. We selected randomised controlled trials (RCTs) and controlled observational studies of any ICS (duration at least 12 months) compared to non-ICS use in patients with asthma. We conducted meta-analysis of ORs for fractures, and mean differences in bone mineral density. Heterogeneity was assessed using the I2 statistic. Results: We included 18 studies (7 RCTs and 11 observational studies) in the systematic review. Meta-analysis of observational studies did not demonstrate any significant association between ICS and fractures in children (pooled OR 1.02, 95% CI 0.94 to 1.10, two studies), or adults (pooled OR 1.09, 95% CI 0.45 to 2.62, four studies). Three RCTs and three observational studies in children reported on bone mineral density at the lumbar spine, and our meta-analysis did not show significant reductions with ICS use. Three RCTs and four observational studies in adults reported on ICS use and bone mineral density at the lumbar spine and femur, with no significant reductions found in the meta-analysis compared to control. Conclusions ICS use for ≥12 months in adults or children with asthma was not significantly associated with harmful effects on fractures or bone mineral density

Bone: An Acute Buffer of Plasma Sodium during Exhaustive Exercise?

Both hyponatremia and osteopenia separately have been well documented in endurance athletes. Although bone has been shown to act as a “sodium reservoir” to buffer severe plasma sodium derangements in animals, recent data have suggested a similar function in humans. We aimed to explore if acute changes in bone mineral content were associated with changes in plasma sodium concentration in runners participating in a 161 km mountain footrace. Eighteen runners were recruited. Runners were tested immediately pre- and post-race for the following main outcome measures: bone mineral content (BMC) and density (BMD) via dual-energy X-ray absorptiometry (DEXA); plasma sodium concentration ([Na+]p), plasma arginine vasopressin ([AVP]p), serum aldosterone concentration ([aldosterone]s), and total sodium intake. Six subjects finished the race in a mean time of 27.0±2.3 h. All subjects started and finished the race with [Na+]p within the normal range (137.7±2.3 and 136.7±1.6 mEq/l, pre- and post-race, respectively). Positive correlations were noted between change (Δ; post-race minus pre-race) in total BMC (grams) and [Na+]p (mEq/l) (r=0.99;

Bisdemethoxycurcumin and Its Cyclized Pyrazole Analogue Differentially Disrupt Lipopolysaccharide Signalling in Human Monocyte-Derived Macrophages

open11noSeveral studies suggest that curcumin and related compounds possess antioxidant and anti-inflammatory properties including modulation of lipopolysaccharide- (LPS-) mediated signalling in macrophage cell models. We here investigated the effects of curcumin and the two structurally unrelated analogues GG6 and GG9 in primary human blood-derived macrophages as well as the signalling pathways involved. Macrophages differentiated from peripheral blood monocytes for 7 days were activated with LPS or selective Toll-like receptor agonists for 24 h. The effects of test compounds on cytokine production and immunophenotypes evaluated as CD80+/CCR2+ and CD206+/CD163+ subsets were examined by ELISA and flow cytometry. Signalling pathways were probed by Western blot. Curcumin (2.5–10 μM) failed to suppress LPS-induced inflammatory responses. While GG6 reduced LPS-induced IκB-α degradation and showed a trend towards reduced interleukin-1β release, GG9 prevented the increase in proinflammatory CD80+ macrophage subset, downregulation of the anti-inflammatory CD206+/CD163+ subset, increase in p38 phosphorylation, and increase in cell-bound and secreted interleukin-1β stimulated by LPS, at least in part through signalling pathways not involving Toll-like receptor 4 and nuclear factor-κB. Thus, the curcumin analogue GG9 attenuated the LPS-induced inflammatory response in human blood-derived macrophages and may therefore represent an attractive chemical template for macrophage pharmacological targeting.openTedesco, Serena; Zusso, Morena; Facci, Laura; Trenti, Annalisa; Boscaro, Carlotta; Belluti, Federica; Fadini, Gian Paolo; Skaper, Stephen D.; Giusti, Pietro; Bolego, Chiara; Cignarella, AndreaTedesco, Serena; Zusso, Morena; Facci, Laura; Trenti, Annalisa; Boscaro, Carlotta; Belluti, Federica; Fadini, Gian Paolo; Skaper, Stephen D.; Giusti, Pietro; Bolego, Chiara; Cignarella, Andre

Exploring adaptation & self-adaptation in autonomic computing systems

This panel paper sets out to discuss what self-adaptation means, and to explore the extent to which current autonomic systems exhibit truly self-adaptive behaviour. Many of the currently cited examples are clearly adaptive, but debate remains as to what extent they are simply following prescribed adaptation rules within preset bounds, and to what extent they have the ability to truly learn new behaviour. Is there a standard test that can be applied to differentiate? Is adaptive behaviour sufficient anyway? Other autonomic computing issues are also discussed

Inhibitory effect of calotropis gigantea extract on ovalbumin-induced airway inflammation and arachidonic acid induced inflammation in a murine model of asthma

The root of Calotropis gigantea has been reported as a traditional folkloric medicine in treatment of asthma in the Indian literature. Root contain α-and β-amyrin are reported to possess anti-lipoxygenase activity. Present study was undertaken to investigate the effect of methanolic extract of root of Calotropis gigantea (Linn.) R.Br. (CG) on ovalbumin induced asthma and arachidonic acid induced paw edema in rats. In ovalbumin induced asthma, rats were sensitized and challenged with ovalbumin (OVA). The effect of CG at 100, 200, 400 mg/kg, p.o. on inflammatory cell count, level of nitric oxide and total protein in bronchalveolar lavage (BAL) fluid, lung antioxidant enzymes (LPO, GSH, SOD, Catalase) and histopathological changes were observed. Change in paw edema volume was measured in arachidonic acid induced paw edema model. CG at 200, 400 mg/kg, p.o. showed significant inhibition of eosinophil, neutrophil and lymphocyte and total leukocyte count in bronchalveolar lavage (BAL) fluid (p<0.05). In BAL fluid, CG significantly reduced the nitric oxide and total protein levels (p<0.05). CG significantly restored the levels of GSH, SOD and LPO in lungs (p<0.01). CG at doses of 200, 400 mg/kg significantly inhibited OVA induced histological changes (p<0.01). CG significantly reduced the arachidonic acid induced paw edema volume (p<0.05). These results suggest that CG may prove to be potential therapeutic drug for treating asthma owing to its anti-inflammatory, anti-lipoxygenase and antioxidant activities. \ud \u

The frequency of osteogenic activities and the pattern of intermittence between periods of physical activity and sedentary behaviour affects bone mineral content: the cross-sectional NHANES study

BACKGROUND: Sedentary behaviours, defined as non exercising seated activities, have been shown to have deleterious effects on health. It has been hypothesised that too much sitting time can have a detrimental effect on bone health in youth. The aim of this study is to test this hypothesis by exploring the association between objectively measured volume and patterns of time spent in sedentary behaviours, time spent in specific screen-based sedentary pursuits and bone mineral content (BMC) accrual in youth. METHODS: NHANES 2005–2006 cycle data includes BMC of the femoral and spinal region via dual-energy X-ray absorptiometry (DEXA), assessment of physical activity and sedentary behaviour patterns through accelerometry, self reported time spent in screen based pursuits (watching TV and using a computer), and frequency of vigorous playtime and strengthening activities. Multiple regression analysis, stratified by gender was performed on N = 671 males and N = 677 females aged from 8 to 22 years. RESULTS: Time spent in screen-based sedentary behaviours is negatively associated with femoral BMC (males and females) and spinal BMC (females only) after correction for time spent in moderate and vigorous activity. Regression coefficients indicate that an additional hour per day of screen-based sitting corresponds to a difference of −0.77 g femoral BMC in females [95% CI: -1.31 to −0.22] and of −0.45 g femoral BMC in males [95% CI: -0.83 to −0.06]. This association is attenuated when self-reported engagement in regular (average 5 times per week) strengthening exercise (for males) and vigorous playing (for both males and females) is taken into account. Total sitting time and non screen-based sitting do not appear to have a negative association with BMC, whereas screen based sedentary time does. Patterns of intermittence between periods of sitting and moderate to vigorous activity appears to be positively associated with bone health when activity is clustered in time and inter-spaced with long continuous bouts of sitting. CONCLUSIONS: Some specific sedentary pursuits (screen-based) are negatively associated with bone health in youth. This association is specific to gender and anatomical area. This relationship between screen-based time and bone health is independent of the total amount of physical activity measured objectively, but not independent of self-reported frequency of strengthening and vigorous play activities. The data clearly suggests that the frequency, rather than the volume, of osteogenic activities is important in counteracting the effect of sedentary behaviour on bone health. The pattern of intermittence between sedentary periods and activity also plays a role in bone accrual, with clustered short bouts of activity interspaced with long periods of sedentary behaviours appearing to be more beneficial than activities more evenly spread in time